Automatic reclosing circuit-breaker system



1929- c. MCL. MOSS El AL 1, 31,

AUTOMATIC RECLOSING CIRCUIT BREAKER SYSTEM Filed Dec. 21, 1922 2 Sheets-sheaf l WITNESSES: INVENTOR S Charles I10 L. Moss.

- William R. Farley and Alfred A. Peierson V BY M M awr/ TOR'NEY Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE CHARLES MCL. MOSS, OF PITTSBURGH, AND WILLIAM R. FARLEY AND ALFRED J. A. PETERSON, OF WILKINSBURG, PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA AUTOMATIC RECLOSTNG CIRCUIT-BREAKER SYSTEM Application filled December 21, 1922. Serial No. 808,300.

Our invention relates to automatic systems for reclosing circuit interrupters and particularly to selective reclosing systems.

One object of our invention is to provide a reclosing system that may be employed with a plurality of feeder circuits to effect the automatic and selective control of any one of the feeder circuits upon the occurrence of predetermined abnormal conditions therein.

Another object of our invention is to provide a system, of the above-indicated character, wherein a single reclosing unit may operate' to reclose one feeder circuit at a time in order to preclude an abnormally heavy drain upon a control source of energy, and an excessive shock on the power system.

A further object of our invention is to provide a svstem, of the above-indicated character, in w llCh a single controlling unit may serve to control a plurality of feeder circuits in a predetermined sequence.

Another object of our invention is to provide a control unit in a system, of the aboveindicated character, that shall be operative, upon the occurrence of abnormal conditions in one or more of the circuits to be controlled, to operate the control devices associated with each circuit through a predetermined cycle or schedule before moving to control another feeder subsequently disposed in the predetermined sequence.

In practicing our im'ention, we provide for each circuit of the several feeders a control relay for the closing coil and a lock-out relay for precluding the energization of the coil when a predetermined abnormal condition persists for a predetermined interval of time. We also provide for the control of the several feeders a single control unit comprising a selector relay switch, a timing relay and also what we term a set-up or control relay for the selector.

When a circuit interrupter is opened by reason of abnormal conditions in the circuit,

the selector actu ates a drum controller switching mechanism to subject the closing coil of the interrupter to the controlling influence of the timing and the set-up relays. The interrupter is thereupon reclosed.

to operate to preclude further energization of the closing coil.

If the interrupter should remain closed after any one of the three reclosures, the timing and the set-up relays will be disconnected from the closing mechanism of the interrupter. If, in the meantime, the interrupter of another feeder circuit has been opened by reason of faulty conditions therein, the selec tor will move the control of the timing and the set-up relays to a switch associated with the second faulty circuit. The same cycle or schedule of operations is effected until the interrupter of that circuit is either reclosed or locked out. 4

The system disclosed in this application includes certain features which constitute the subject-matter of copending application, Serial No. 632,274, filed April 16, 1923 by Alfred J. A. Peterson, and assigned to the assignee of the present application.

Figure 1 of the accompanying drawings is a diagrammatic view of an electrical system illustrating the arrangement of the control apparatus for two feeder circuits connected to operate in accordance with our invention.

Fig. 2 is a schematic diagrammatic view illustrating, in simplified form, the several circuit connections of the system that is illustrated in Fig. 1.

Referring to the accompanyin drawings, energy is supplied from a supp y circuit 1 to a plurality of feeder circuits 2 and 3 through circuit interrupters 4 and 5, respectively. The interrupter 4 is provided with a closing coil 10 and a trip coil 11. The circuit of the trip coil 11 is controlled by an overload relay 12 which is energized in accordance with the current traversin the feeder circuit through a current trans ormer 13.

The interrupter 4 is also provided with two auxiliary interlock switches 14 and 15 that are open when the main contacts of the circuit interrupter are open, and two switches 16 and 17 that are closed when the main contacts of the interrupter are open.

The circuit of the closing coil 10 of the interrupter is controlled by an auxiliary relay switch 18, the operating circuit of which is controlled by a relay 19, which we shall hereafter term the cut-H relay.

The function of the cut-0E relay 19 is to open the circuit of the closing coil by deenergizing the relay switch 18 after each 010- sure of the interrupter 4.

The relay 19 comprises two switches 20 and 21 that are normally closed and a switch 22 that is normally open when the relay is deenergized. The relay further comprises an operating coil 23 that serves to actuate the switches 20, 21 and 22 from their de-energized positions and a holding coil 24 that serves to maintain the switches in their energized positions so long as the holding coil is energized, irrespective of whether the operating coil 23 remains energized or not. The construction of this relay is such that the holding coil 24 does not have sufficient torque to operate the relay, but merely sufficient to maintain the relay in its energized position after it has been actuated thereto by the operating coil 23.

The interrupter 4 of the feeder circuit 2 is also provided with another relay 26, which we shall hereafter term the look-out relay. The function of the lockout relay is to preclude further automatic control of the interrupter after a-fau'lt occurs and persists beyond the time required to actuate the interrupter through a predetermined cycle of operations. The lock-out relay 26 comprises two switches 27 and 28 that are open in the deenergized position of the relay, an operating coil 29 that serves to actuate the switches to their respective closed positions, and a latch that serves to maintain them in closed position, irrespective of the energization-of the coil 29, and a releasing coil 30 for withdrawing the latch to permit the switches 27 and 28 to open.

The control apparatus associated with the interrupter 4 comprises further a time-element relay 32 that is energized from a po- 7 tential transformer 38 which is connected to the feeder circuit 2. The relay 32 may be adjusted to operate after a time interval of the order of two seconds.

A resistor is connected in parallel with the operating coil of relay switch 18 to provide an additional current-carrying path for the operating coil of another control relay, as will be hereinafter explained.

The feeder circuit 3 and the interrupter 5 associated therewith are provided with control equipment similar to that enumerated above as associated with the circuit 2 and the interrupter 4. The apparatus that is associated with the interrupter 5 will be referred to by numerals similar to those applied to apparatus of feeder circuit 2 except in the 100 series, for example, the closing coil 10 closing coil 110 of the interrupter 5.

Any number of feeder circuits, equipped with control apparatus similar to that hereinabove described, may be controlled, in any predetermined sequence, by the following apparatus, that is arranged to constitute a single control unit. Such apparatus comprises, in general, a motor-driven sequence switch or selector 51, a set-up relay 52 and a timing relay 53.

The selector 51 comprises a unidirectional motor 54 and a drum controller comprising a plurality of segments 55 that are adapted, in different positions of the controller, to severally engage a plurality of stationary contact members 56, 57 and 58. To control more feeder circuits, only an additional contact member need be employed on the drum for each addi tional circuit.

The set-up relay 52 is similar in construction and in operation to the cut-off and the lock-out relays previously described, and it comprises two switches 60 and 61 that are nor mally open, two switches 62 and 63 that are normally closed, an operating coil 64 for actuating the switches and a holding coil 65 for maintaining them in the position to which they are actuated.

The timing relay 53 comprises a motor 68 and a movable bridging member 69 that of the interrupter 4 will correspond to the is controlled thereby through gearing of proper ratio to engage and bridge the three sets of contact members 70, 71 and 72, respectively. The timing relay 53 may be adjusted to cause the bridging member 69 to control the three sets of contact members in a predetermined sequence after predetermined intervals, for example, the relay may be adjusted to effect the bridging of the contact members 70 thirty seconds after the relay is energized, the bridging of the contact members 71 one minute later and the bridging of the contact members 72 two minutes later. These time intervals are specified merely. by way of example and they may be respectively adjusted to suit the conditions of any particular system, as desired.

The timing relay is of the clutch type and closed to energize the associated circuits.

Upon the occurrence of abnormal conditions in the circuit 2, the interrupter 4 opens. The following operation thereupon occurs.

As will be seen by referring to circuit A of Fig. 2, the circuit of the motor 54 of the selector 51 will be energized by the closing of the auxiliary interlock switch 17 of the interrupter 4 to complete a circuit from the -cuit thereof may be traced, upon reference to circuits D and G, from the negative control bus 76 through the operating coil 64 of the set-up relay, the contact members 56 and 57 and the bridging segments 55, conductors 77 and 78, the switch 20 of the cut-off relay 19, and the operating coil of the relay switch '18 and the resistor 35 in parallel, to the positive conductor 75. The resistor 35 serves to provide an additional current-carrying path that will permit sufi'icient current to energize the operating coil 64 to operate the set-up relay 52. The relay switch 18, however, is not energized to a sufiicient degree to cause it to close.

Immediately upon the, energization, how ever, of the operating coil 64. the holding coil 65, which is always energized in series with the resistor 66 between the positive and negative conductors 75 and 76, illustrated in circuit C, serves to maintain the set-up relay 52 in its energized position. The switches 60 and 61 are thereupon closed and the switches 62 and 63 are opened. The switch 60 short-circuits the operating coil 64, as will be seen by reference to the circuit D of Fig. 2, and thereupon reduces the resistance of the circuit G including the relay switch 18, sutliciently to permit that switch to close. The closing coil 10 of the interrupter is thereupon energized to close the interrupter.

As soon as the interrupter 4 closes, interlock switch 15 closes circuit F to connect the operating coil 23\of the cut-off relay 19 between the positive and negative conductors 75 and 76. The cut-off relay 19 is thereupon actuated to close switch 22 and to open switches 20 and 21. Switch 20, in

opening, opens the circuit of the closing coil.

of relay switch 18, whereupon the closing coil 10 is de-energized. This operation is illustrated in circuit G of Fig. 2. The cutoff relay 19 is then maintained in energized position by the holding coil 24, circuit H, the circuit of which is completed from the positive conductor 7 5 to the negative conductor 7 6 through a resistor 73, control bus conductor 77, operating coil 24, conductor 78,

contact members 56 and 57 and segments of the selector, and switch ofthe set-up relay 52.

If the fault which caused the-interrupter to open is cleared, the interrupter 4 will remain closed. If the faulty condition persists, however, the interrupter 4 will immediately be opened by the operation of the overload relay 12 after a time interval depending upon its time setting.

Let it be assumed first that the faulty condition is cleared and that the interrupter 4 remains closed. Under such conditions, the relay 32 will be energized to close its switch after the predetermined interval for which it has been set to operate, for example, two seconds. The switch 32, in closing, short-circuits the holding coil of the set-up relay 52 through conductors 79 and 80. switch conductor 78, contact mem- 0.4 bers 56 and 57, segments 55 of the selector,

switch 60 and holding coil 65 of the setup rcla y through conductor 81. The setup relay 52 is thereupon permitted-to return to its initial position to open the switch 60 and remove control potential from the segments 55 of .the selector 51. The interrupter remains closed and the control apparatus is tie-energized.

Let it now be assumed that the faulty condition of the circuit 2 is a persistent one and that the interrupter is immediately reopened after its first reclosure. The relay 32 has not had suflicient time to close-its switch since, normally, its time setting is greater than the time setting of the overload relay 12. The set-up relay 52 is therefore still in its energized position. Switch 61 of set-up relay 52 connected the operating motor 68 of the timing relay 53 between the control conductors 75 and 76 immediately upon the actuationof the set-up relay 52. Since the interrupter was reopened within two seconds after its first reclosure, by reason of the persisting faulty condition, the timing relay 53 will continue to operate until the contact members 70 are bridged by the bridging member 69.

The bridging of the contact members 70 completes a short-circuit around the holding coil 24 of the cut-off relay 19 which has heretofore remained energized. The cutoff relay 19 is thereupon permitted to return to its initial position. As illustrated by circuits'D and H, the short-circuit around the holding coil 24 may be traced from one terminal of the coil through conductors 78, the contact members 56 and 57 and the segments 55 of the selector, the contact members 70 of the timing relay 53, conductors 82 and 77 to the other terminal of the coil 24.

When the cut-off relay 19 returns to its initial position, the switch 20 is closed and the circuit of the operating coil of the auxiliary relay switch 18 is re-energized, as previously described and illustrated in circuit G, whereupon the closing coil 10 is energized to reclose the interrupter 4 a second time.

If the feeder circuit 2 should now be clear of abnormal conditions, the set-up relay 52 will be de-energized, as previously described, and the control unit will be available for the control of another feeder circuit. If, however, the faulty condition of. circuit 2 still persists, the interrupter 4 will again be opened, and, aftera predetermined interval determined by' the setting between the contact members 70 and 71, the latter set of contact members will be bridged to effect the third reclosure of the interrupter 4.

As previously explained, the control unit will be disconnected if the feeder circuit is now clear of faulty or abnormal conditions. If the abnormal conditions still persist after such third reclosure, the timing relay 53 will continue to operate until the contact members 7 2 are bridged. The operating coil 29 of the lock-out relay 26 will thereupon be energized, as illustrated in circuits E and K, from the positive control conductors 75 through the set of contact members 72, a common conductor 83, the operating coil 29 of the lock-out relay 26, conductor 78, contact members 56 and 57 and segment 55 of the selector and switch 60 of the setup relay 52 to the negative conductor 76.

The lock-out relay 26 is thereupon actuated to its energized position whereupon a circuit the holding coil 65 is completed by the switch 27 through the holding coil. 30 that maintains the latter energized to hold the lock-out relay in its energized position.

Simultaneously, switch 28 of the lookout relay closes and co-Operates with the switch 22 of the cut-off relay 19 which is still in its energized position to short-circuit the holding coil 65 of the set-up relay 52. This circuit, as illustrated by circuits C and J in Fig. 2, may be traced from one terminal of through conductor 81, conductor 79, switch 28 of look-out relay 26, switch 22 of cut-off relay 19, conductor 78, contact members 56 and 57 and segments of the selector, switch 60 of the set-up relay 52 to the other terminal of the holding coil of the latter relay. The set-up relay 52 is thereupon permitted to return to its initial position. In such position, the swltch 63 is closed to permit the energization of the selector motor 5 L when any other circuit interrupter is opened by reason of abnornial conditions in the associated circuit.

Similarly, the closure of switch 62 of the set-up relay 52 short-circuits the motor 68 and the clutch of the timing relay 53 whereupon the bridging member 69 is permitted to return to its initial position. The respective elements 51, 52 and 53 that constitute the common control equipment are now available to control the next interrupter which may be open.

Our invention thus contemplates the control of an interrupter through a predetermined cycle or schedule of operations unless the faulty condition 'which caused the interrupter'to be opened should be cleared before the last operation of such cycle is performed. Immediately upon cycle of operations or the determination of a. normal condition in the circuit, the control unit is disconnected from the circuit which it has been controlling and is rendered available to control the next interrupter which may be open by reason of abnormal conditions in its associated circuit.

It will be readily seen, from the diagram that is illustrated in Fig. 2, that any number of circuits may be added and controlled in similar manner without disturbing the connections of the present apparatus. Only an additional contact member need be added to the selector 51.

By means of such a system, only a relatively small source of control energy is required and there is no drain thereon as would be the case with more than one circuit interrupter being reclosed simultaneously.

Our system is not limited to the specific apparatus or the specific arrangement thereof that we have illustrated but may be modified without departing from the spirit and scope thereof, as set forth in the ap pended, claims.

We claim as our invention:

1. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuit-controlling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controlling device, means for controlling the closing mechanism of the circuitcontrolling devices in a predetermined sequence, said means operating to control each mechanism in the sequence in a predetermined manner depending upon the condition of the associated circuit before moving to control the mechanism of a circuit subsequently disposed in the sequence.

2. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuit-controlling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuthe completion of such ating the tripping mechanism of the associ ated controlling device, means forcontrolling the closing mechanism of said associated device, unit means for controlling said closing mechanism-controlling means through a predetermined cycle of operation, anda selector for selectively subjecting the mechanism-controlling means to the closing unit controlling means.

3. In a power distributing system, the com-- bination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuitcontrolling device in each feeder circuit provided With closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controlling device, means for controllin the closing mechanism of said associated device, unit means for controlling said closing mechanism-controlling means through a predetermined cycle of operation, a selector for selectively subjecting the closing mechanismcontrolling means to the unit controlling means, and means for controlling the operation of the selector.

4. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuit-controlling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controlling device, means for controlling the closing mechanism of said associated device, unit means for controlling said closing mechanism-controlling means through a predetermined cycle of operation, a selector for selectively subjecting the closing mechanism-controlling means to the unit controlling means, and means controlled by a feeder circuit controlling device for con- ,trolling the selector.

5. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuit controlling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controlling device, means for controlling the closing mechanism of said associated device, unit means for controlling said closing mechanism-controlling means through a predetermined'cycle of operation, a selector for means, and means responsive to a predetermined condition of a feeder circuit for controlling the selector.

6. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuitcontrolling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controllingdevice, means for controlling the closing mechanism of said associated device, unit means for controlling said closing mechanism-controlling means through a predetermined cycle of operation, a selector for selectively subjecting the closing mechanism-controlling means to the unit controlling means, and means whereby the selector is rendered ineffective while a closing 'mechanism of a feeder circuit controlling device is being operated through its predetermined cycle of operations.

7 In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuitcontrolling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controlling device, means for controlling the closing mechanisms of the circuit-controlling devices, and unit means operative, upon the occurrence of a faulty condition in a feeder circuit that causes the actuation of the circuit-com trolling device thereof, to single out the faulty circuit. and to actuate the associated circuitcontrolling device through a predetermined cycle of operations to reconnect the feeder circuit to the supply circuit if the faulty condition has cleared but to lock out the faulty circuit if the faulty condition persists after the aforementioned cycle of operations is com pleted.

8. In a power distributing system, the combination with a supply circuit. a plurality of feeder circuits energized therefrom, a circuit controlling device in each feeder circuit provided with closing and tripping mechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated coninc trolling device, a single selector operative upon the occurrence of an abnormal condition in any of the feeder circuits to select the circuit and to reconnect it to the supply circuit if the abnormal condition be cleared but to lock out said circuit to preclude further reconnection thereof to the supply circuit if the abnormal condition persists.

9. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuitcontrolling device in each feeder circuit provided with closing and tripping mechanism,

for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to apredetermined abnormal condition in a feeder circuit for actuating the tripping mechanism of the associated controllingdevice,means for severally controlling the closing mechanisms of the circuit-controlling devices, unit means for controlling said closing mechanism-controlling means and a single means controlled in accordance with the condition of a circuit being controlled for controlling the unit means.

10. In a power distributing system, the combination with a supply circuit, a plurality of feeder circuits energized therefrom, a circuit-controlling device in each feeder circuit provided with closing and trippingmechanism, for connecting said feeder circuits to the supply circuit and a common source of control energy for the closing mechanisms, of means responsive to a predetermined abnormal condition in a feeder circuit for actuating iliary systems to be connected thereto, of means for individually disconnecting an auxiliary system from the common system in response to predetermined conditions and means comprising a set-up means and a se lector for selectively reconnecting the auxiliary systems to the common system in a predetermined sequence.

In testimony whereof, we have hereunto subscribed our names this 14th day of December, 1922.

CHARLES MoL. MOSS. ALFRED J. A. PETERSON. WILLIAM R. FARLEY.

the tripping mechanism of the associated means for controlling the of the circuit-controlling for picking out a faulty circuit, and means for then controlling the circuit-controlling device of that circuit in accordance with a predetermined schedule.

11. The combination with a plurality of circuits severally having a circuit-controlling device associated therewith, of means severally responsive to a predetermined condition of the circuits for actuating the controlling devices to one position, unit means for actuating said devices to another predetermined position and a selector for controlling said unit means.

12. The combination with a plurality of circuits severally having a circuit-controlling controlling device, closing mechanisms devices, a selector device associated therewith, of means severally responsive to a predetermined condition of the circuits for actuating the controlling devices to one position, unit means, for actu ating said devices to another predetermined position, a selector for controlling said unit means, and means controlled by the circuitcontrolling devices for controlling the selector.

13. The combination with a common power distribution system and a plurality of aux- 

